Contributions are welcome, and they are greatly appreciated! Every little bit helps, and credit will always be given.
You can contribute in many ways:
Report bugs at https://github.com/ShortestPathLab/flatland/issues.
If you are reporting a bug, please include:
- Your operating system name and version.
- Any details about your local setup that might be helpful in troubleshooting.
- Detailed steps to reproduce the bug.
Look through the Repository Issue Tracker for bugs. Anything tagged with "bug" and "help wanted" is open to whoever wants to implement it.
Look through the Repository Issue Tracker for features. Anything tagged with "enhancement" and "help wanted" is open to whoever wants to implement it.
flatland could always use more documentation, whether as part of the official flatland docs, in docstrings, or even on the web in blog posts, articles, and such. A quick reference for writing good docstrings is available at : https://docs.python-guide.org/writing/documentation/#writing-docstrings
The best way to send feedback is to file an issue at https://github.com/ShortestPathLab/flatland/issues.
If you are proposing a feature:
- Explain in detail how it would work.
- Keep the scope as narrow as possible, to make it easier to implement.
- Remember that this is a volunteer-driven project, and that contributions are welcome :)
Ready to contribute? Here's how to set up flatland for local development.
Fork the flatland repo on https://github.com/ShortestPathLab/flatland .
Clone your fork locally:
$ git clone git@github.com:ShortestPathLab/flatland.git
Install the software dependencies with uv. (This assumes you have uv installed by following the instructions here. You do not need to install Python yourself — uv reads
.python-versionand provisions the right interpreter for you.)$ uv sync
This creates a
.venvvirtual env fromuv.lock, with the project and all development dependencies installed.Create a branch for local development:
$ git checkout -b name-of-your-bugfix-or-feature
Now you can make your changes locally.
When you're done making changes, check that your changes pass ruff and the tests:
$ uv run ruff check flatland tests examples benchmarks $ uv run pytest
uv run ruff check --fixapplies the safe fixes automatically, anduv run ruff formatreformats the code.Prefixing a command with
uv runruns it inside the project virtual env, re-syncing it first if the lockfile changed. Alternatively, activate.venvyourself and drop the prefix.Commit your changes and push your branch to GitHub:
$ git add . $ git commit -m "Addresses #<issue-number> Your detailed description of your changes." $ git push origin name-of-your-bugfix-or-feature
Submit a pull request through the GitHub repository website.
Before you submit a pull request, check that it meets these guidelines:
- The pull request should include tests.
- If the pull request adds functionality, the docs should be updated. Put your new functionality into a function with a docstring, and add the feature to the list in README.md.
- The pull request should work for Python 3.14. Make sure that the tests pass before asking for a review.
- Although we cannot enforce it technically, we ask for pull requests to be reviewed by at least one core member in order to ensure that the Technical Guidelines below are respected and that the code is well tested.
- When a pull request is merged, source branches should be deleted and commits squashed.
To run a subset of tests:
$ py.test tests.test_flatlandA reminder for the maintainers on how to cut a release. Flatland is not published to a package index; a release is simply a tagged commit that users install from GitHub. Make sure all your changes are committed, then run:
$ bumpversion patch # possible: major / minor / patch
$ git push
$ git push --tagsPlease adhere to the general Clean Code principles, for instance we write short and concise functions and use appropriate naming to ensure readability.
We use the pylint naming conventions:
module_name, package_name, ClassName, method_name, ExceptionName, function_name, GLOBAL_CONSTANT_NAME, global_var_name, instance_var_name, function_parameter_name, local_var_name.
Docstrings should be formatted using numpydoc.
- We use importlib-resources to read from local files.
Sample usages:
from importlib_resources import path with path(package, resource) as file_in: new_grid = np.load(file_in)
And:
from importlib_resources import read_binary load_data = read_binary(package, resource) self.set_full_state_msg(load_data)
Renders the scene into a image (screenshot)
renderer.gl.save_image("filename.bmp")
We use Type Hints (PEP 484) for better readability and better IDE support.
Have a look at the Type Hints Cheat Sheet to get started with Type Hints.
Caveat: We discourage the usage of Type Aliases for structured data since its members remain unnamed.
For structured data containers for which we do not write additional methods, we use NamedTuple instead of plain Dict to ensure better readability by
Members of NamedTuple can then be accessed through .<member> instead of ['<key>'].
If we have to ensure some (class) invariant over multiple members (for instance, o.A always changes at the same time as o.B), then we should uses classes instead, see the next section.
We use classes for data structures if we need to write methods that ensure (class) invariants over multiple members, for instance, o.A always changes at the same time as o.B. We use the attrs class decorator and a way to declaratively define the attributes on that class:
We use the abc class decorator and a way to declaratively define the attributes on that class:
And then
# abc_subclass.py import abc from abc_base import PluginBase class SubclassImplementation(PluginBase): def load(self, input): return input.read() def save(self, output, data): return output.write(data) if __name__ == '__main__': print('Subclass:', issubclass(SubclassImplementation, PluginBase)) print('Instance:', isinstance(SubclassImplementation(), PluginBase))
We discourage currying to encapsulate state since we often want the stateful object to have multiple methods (but the curried function has only its signature and abusing params to switch behaviour is not very readable).
Thus, we should refactor our generators and use classes instead.